JPH0124510B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION US Pat. No. 3,879,293 (corresponding to Japanese Patent Publication No. 60-56497) describes a membrane diffuser having an inflatable member for pressurization and sealing. The inflatable member is U-shaped so as to be located around the largest surface and bottom surface of the stack of diffusion membranes separated by the membrane support member means, and the inflatable member has two different Forms a plugging channel for the fluid.

The purpose of the inflatable member, whether a flat member as is well known in the prior art or the U-shaped member of the above patent, is to prevent excessive widening of the fluid passages in the stack when pressurized fluid is supplied. selectively applying pressure to the membrane stack through expansion while holding the stack within a rigid casing to prevent This is particularly important if the device is intended for use in blood oxygenation devices, artificial kidneys, etc.

The present invention provides a means for increasing the relative amount of surface area of the laminate that is affected by the inflatable stuffing. Also provided are novel improvements in laminate end seals that further reduce the possibility of leakage from the ends of the membrane laminate.

According to the present invention, there is provided a membrane diffusion device in which a laminate in which a sheet-like diffusion membrane and a sheet-like support thereof are overlapped and folded in a zigzag shape is housed in a casing together with an inflatable member for compressing the laminate. be done. Although the casing walls generally have small clearance angles as an inevitable result of economical molding processes, the laminate itself generally has parallel, opposed sides.

According to the invention, spaced rigid padding members are located around each end of the laminate between the laminate and the casing inner wall having the clearance angle at the outer corners of the laminate. . The rigid stuffing member is correspondingly inclined at an angle corresponding to the pull-out angle of the inner casing wall and is balanced to compress the laminate generally to the same extent over the entire length of the rigid stuffing member. .

Preferably the padding member fits around each outer corner of the laminate and is in compressive contact with both the sides and ends of the laminate near each corner for a bidirectional compressive action on the laminate. with a corresponding tapered element.

The effect of this is that the laminate is centered within the casing and the laminate is stacked in such a way that uneven compression of the laminate that occurs when inserting a membrane laminate into a casing with slightly non-parallel walls is eliminated. It involves constantly and evenly compressing the extremities of the body. This helps strengthen the end seal of the laminate, which can be, for example, the embedded seal described in U.S. Pat. No. 3,757,955, and applies a constant compressive force to the embedded seal element to prevent seal failure. . The rigid padding member also stiffens the ends of the laminate, which stiffening reduces the possibility of delamination at the end of the laminate to the end seal due to perturbing pressure.

Additionally, each rigid tapered padding member at each end of the laminate is provided in an integral H-shape by a crossbar member to facilitate assembly and further support the laminate ends relative to the casing. Preferably they are connected together to form a unit.

Referring to the drawings, FIG. 1 is a perspective view of a blood oxygenation device employing the present invention, with some interior portions shown in phantom.

2 is a vertical cross-sectional view of the end of the blood oxidizer of FIG. 1 taken along line 2--2 of FIG. 1; FIG.

3 is a partial cross-sectional view of the end of the blood oxygenator taken along line 3--3 of FIG. 2; FIG.

4 is an isolated, enlarged cross-sectional view of the inflatable member used in FIGS. 1-3, taken along line 4--4 of FIG. 3; FIG.

FIG. 5 is a partial cross-sectional view similar to FIG. 4 of the second embodiment of the inflatable member described above.

Referring to FIGS. 1-4, the illustrated blood oxygenation device is similar to that shown in U.S. Pat. No. 3,879,293, but with the improvements described herein.

Oxygenation device 10 comprises a casing 12 closed with a top member 14 and includes a sealed blood inlet 16 and outlet 18.

Openings 20, 22 in the lower side of the casing 12 are for connection to oxygen inlets and outlets, respectively, the flow of oxygen being normally countercurrent to the flow of blood.
In particular, oxygenator 10 is adapted for use in the apparatus described in US Pat. No. 4,061,470 for oxygenating the blood of patients undergoing cardiac surgery or the like. A folded membrane stack 24 as described in the previously cited patents and in particular U.S. Pat. No. 3,757,955 is provided;
A number of separate flow paths connect the blood inlets and outlets 16,1
8 and in flow communication with oxygen inlets and outlets 20,22.

Around the central part of the laminate 24, the laminate 24
A U-shaped inflatable member 26 is located for pressurizing the central portion of the. Inflatable member 2
Located adjacent to the outer edge of 6 is a longitudinally extending cutout 28 of the folded membrane support backing 29, which cutout allows for uniform flow across the majority of the membranes in the stack 24. , which serves as a manifold means for distributing blood and oxygen to their respective channels throughout the folded area of the membrane. The ends 25 of the stack 24 are sealed with a potting compound, eg, as described in the previously cited patents, to prevent leakage out of the ends of the membrane stack 24 from the respective channels. Cover 14 is correspondingly sealed to casing 12.

According to the invention, rigid padding member means 30 located at each end of casing 12 provide constant compression against the ends of laminate 24 to enhance the potted end sealing ability. do. As shown, each padding member means 30
includes a pair of tapered rigid upright members 32 connected together by a cross member 34 to form a generally H-shaped structure, and is manufactured from polyethylene, polystyrene, etc. for a simple and inexpensive molding operation. It can be manufactured by. The potted ends of the laminate 24 are located between tapered members 32 at each end of the casing 12. Tapered member 32 and laminate 24 are compressed between the tapered members at the ends of the laminate, which also compress the casing 12 to enhance the sealing ability of the potted ends of the laminate. It is balanced by adhering closely to the inner wall.

As shown in FIGS. 2 and 3, side walls 36 and end walls 38 of container 12 are not parallel to each other;
An inner wall is formed that slightly expands outward from the bottom wall 31. The reason for this is that a small amount (e.g.
1°) Designing the casing 12 so as to have an outward taper or a draw angle
This is because there are very important economic benefits in the molding process that can be utilized.

According to the present invention, as shown in FIG. 2, the tapered member 32 is
has an increasing thickness from bottom to top so that the inner surface 40 of the tapered member is generally parallel and its outer surface flares in a manner that corresponds to the clearance angle of housing 12.

Each tapered member 32 has an end flange member 42 that serves to hold the ends of the laminate 24 in precise positional relationship, and the corners of the laminate 24 are connected to each tapered member 32 and the flange 42. It fits into the corner 44 formed between the two.

As shown in FIG.
The inner surfaces of 8 also have outward clearance angles, and each flange 42 is correspondingly tapered so that their inner surfaces are parallel to each other, while their outer surfaces follow the clearance angle of wall 38. spread in a corresponding manner.

The resulting H-shaped rigid padding member 30 is positioned around the corner of the membrane stack 24 and can be housed within the casing 12 .
Despite the fact that the walls of 2 diverge at a small draft angle, they provide generally constant lateral compression against the ends of the stack 24 in most of their vertical positions. As a result of this, the rigid padding members 30 with their respective shapes, particularly in the upper portions of the ends of the laminate 24, are compressed by the amount of compression felt in the lower portions of the laminate ends by the tapered shape of the upright members 32. Provide substantially equal amounts of compression. This eliminates the otherwise varying effects of the tapered walls of casing 12. The effect of this is to provide further protection against fluid leakage occurring at the sealed end of the laminate 24.

FIG. 4 illustrates details of the construction of the U-shaped inflatable member 26. Inflatable member 26
is generally similar in shape and function to the corresponding U-shaped inflatable member of U.S. Pat.
A flexible inflatable structure containing 0.

At the ends of the member, where in the prior art there were flat peripheral heat seals, only folded edges are seen in the embodiment of FIG. 4. The entire inflatable member 26 consists of a single sheet, which is double folded at the end 52 and
is heat sealed along a line 54 parallel to the line . The heat seal 54 is spaced apart from the edge of the flexible inflatable member 26, except of course at its ends, and the two layers of inflatable member overlap in the manner shown to form a single cross-sectional loop.

The respective opposing sides 56 between the ends 52 of the inflatable member 26 can then be sealed together with a transverse seal or the like to form the sealing member 26.

The member 26 is wrapped around the laminate 24 so that when the stuffing member 30 is installed at the end of the laminate, it is installed in a U-shape. The entire assembly is then assembled into the casing 1 for assembly of the device of the present invention.
It can be stored in 2.

FIG. 5 depicts another embodiment 26a of the inflatable U-shaped member of the present invention, which is substantially similar in construction to the embodiment of FIG. 4 except as shown. In this example, member 26a may be a polyvinyl chloride sheet with a pair of peripheral edges heat-sealed as in the previous embodiment. However, the heat-sealed flange 58 holds the two sides of the inflatable member 26a together and is located inwardly from the outer end of the inflatable member 26a, which outer end is adjacent to the folded membrane wall. 70, the heat seal 58 is located inwardly and folded into the inflatable chamber of the flexible inflatable member 26a. Inflatable member 26
The opposite end of a can be similarly constructed, while the adjacent side can be laterally sealed with a seal line 56a as in the previous embodiment.

The resulting oxygenator is composed of a particularly porous hydrophobic membrane,
Significant advantages of this type of oxygenation device can be achieved, for example, when using polypropylene films with pore sizes of 0.1 micron, which have significantly improved gas transfer rates. At the same time, the present invention provides increased assurance against leaks caused by fluctuating blood pressure within the oxygenator, and also provides substantial improvements in overall oxygen and carbon dioxide transfer rates.

In certain embodiments, the wall 31 shown in FIG.
The width of the chamber of casing 12 at its bottom adjacent to can be approximately 7.87 cm. The corresponding width at the top of the casing can be approximately 8.13 cm to give the casing a draft of 0.254 cm. The taper of member 30 corresponds to this.

The above is provided for illustrative purposes only;
It is not intended to limit the invention as set forth in the claims.

[Brief explanation of drawings]

1 is a perspective view of a blood oxygenation device according to the invention; FIG. 2 is a vertical cross-sectional view of the end of the device of FIG. 1;
3 is a partial sectional view of the end of the device, FIG. 4 is an enlarged sectional view of the inflatable member, and FIG. 5 is an enlarged sectional view similar to FIG. 4 of another embodiment. 10 is a blood oxygenation device, 12 is a casing, 1
6 is a blood inlet, 18 is a blood outlet, 20 is an oxygen inlet, 22 is an oxygen outlet, 24 is a membrane stack, 26 is an inflatable member, and 30 is a stuffing member.

Claims (1)

[Scope of Claims] 1. A laminate in which a sheet-like diffusion membrane and its support, which is also sheet-like, are stacked and folded in a zigzag shape, together with an inflatable member that compresses the laminate, has an inner wall having an open angle. In a membrane diffusion device housed in a casing, rigid padding is interposed between the inner wall of the casing having the cutout angle and the laminate and arranged at intervals at four outer corners of the laminate. said membrane comprising member means, said padding member means being tapered and balanced so as to compress the ends of said laminate to a generally equal degree over the entire length of said padding member means; Diffusion device. 2. The padding member means fits around each corner of the laminate and both sides and ends of the laminate adjacent each corner for a bidirectional compression and positioning action on the laminate. 2. A membrane diffuser according to claim 1, having a correspondingly tapered element in compressive contact with the membrane diffuser. 3. The membrane diffuser of claim 2, wherein opposing sides of the stack are generally parallel to each other. 4. The membrane of claim 3, wherein said rigid padding member means at each end of said laminate are connected together by crossbar members to form an integral H-shaped unit. Diffusion device.